KR20080066298A - An apparatus and method for transmitting data in communication - Google Patents

Abstract

A method and an apparatus for transmitting data in a communication system are provided to omit service flow classification work and efficiently use radio resources by mapping ROHC channels with service flows in a one-to-one ratio. An apparatus for setting up ROHC(Robust Header Compression) channels in a communication system comprises an ROHC context ID creation part(214), an ROHC control part(212), and a service flow searching part(220). The ROHC context ID creation part maps ROHC channels to service flows, based on the transmission characteristics of packet data, in a one-to-one ratio. The ROHC context ID creation part creates IDs to classify the service flows mapped to the ROHC channels. The ROHC control part creates ROHC channels, and transmits ROHC parameter information, which includes information about service flows to be mapped to the ROHC channels in a one-to-one ratio, to the service flow searching part. The service flow searching part receives the ROHC parameter information, creates a new service flow, and transmits the information of the created service flow to the ROHC control part.

Description

An Apparatus and method for transmitting data in communication

1 illustrates a schematic internal hierarchy of a communication system according to a preferred embodiment of the present invention.

2 is an internal configuration diagram of an apparatus for performing mapping between a ROHC channel and a service flow according to an exemplary embodiment of the present invention.

3 is a procedure of establishing an ROHC channel between a base station and a terminal according to a preferred embodiment of the present invention.

The present invention relates to a communication system, and more particularly, to a method and apparatus for transmitting a header compressed packet in a communication system supporting the portable Internet.

In the following, the present invention will be described as an example of a mobile Internet technology of the 802.16e standard as an example of a communication system, but the present invention is applicable to other communication systems.

ROHC (Robust Header Compression), which is one of header compression techniques, is used for a link having a big bit rate (BER) and a round-tip time (RTT). Specifically, the transmitting side initially transmits all the static field information to the receiving side, and the receiving side receives and stores the static field information. Thereafter, the transmitting side transmits only a simple index field to the receiving side, and the receiving side reconstructs static field information corresponding to the index field into information to be transmitted to an upper layer.

Specifically, a compressor inside a terminal or base station in a communication system delivers ROHC packets compressed with a header to a decompressor through a logical connection associated with the header. The logical channel is defined as an ROHC channel and may have different characteristics according to transmission characteristics. In this case, the transmission characteristics include an error rate, a bandwidth, and the like.

Packets with the same transmission characteristics but different protocols or different source addresses and ports each compress their headers using their own context IDs. The protocol includes Real Time Protocol (RTP) / User Data Protocol (UDP) / Internet Protocol (IP), UDP / IP, Electronic Stability Program / IP (ESP), and the like. In this case, in the communication system according to the related art, each context ID is mapped to one transmission connection, that is, a service flow.

Therefore, the method of transmitting the packet to which the ROHC is applied to the header according to the conventional technology as described above has a problem in that the number of packets to which the ROHC can be applied is limited while wasting radio resources.

Accordingly, an object of the present invention, which was devised to solve the problems of the prior art operating as described above, is to provide a method and apparatus for efficiently transmitting ROHC compressed packets having the same characteristics and different context IDs. .

Another object of the present invention is to provide a method and apparatus for mapping a service flow, which is a transport connection of an access network, with a ROHC channel in a 1: 1 manner according to the characteristics of an access network. .

Another object of the present invention is to provide a method and apparatus for specific ROHC parameter negotiation for the mapping.

The method according to an embodiment of the present invention, which was created to achieve the above object, in the channel setting method that supports header compression in a communication system,

Mapping a header compression support channel of the header-compressed packet data and a service flow according to a transmission characteristic of the packet data one-to-one;

And generating an identifier for classifying a service flow mapped to the header compression support channel.

Apparatus according to another embodiment of the present invention, in the communication system, the apparatus for setting a channel that supports header compression,

After header mapping the header compression support channel of the packet data compressed header and the service flow according to the transmission characteristics of the packet data in one-to-one, header compression for generating an identifier for classifying the service flow mapped to the header compression support channel It is configured to include a context identifier generator.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals are used to designate like elements even though they are shown in different drawings, and detailed descriptions of related well-known functions or configurations are not required to describe the present invention. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, the present invention 1: 1 mapping an ROHC channel for transmitting an IP packet to which a ROHC is applied to a header in a communication system with a corresponding service flow according to a transmission characteristic of the IP packet, and distinguishes the mapping. A method and apparatus for generating an ROHC context ID and negotiating ROHC parameters are presented.

Specifically, in the present invention, a service flow, which is a transport connection of an access network corresponding to E, is mapped to a ROHC channel in a transmission characteristic of IP packets to which ROHC is applied to a header in a 1: 1 manner. An ROHC context ID is defined that identifies the service flow mapped to the channel. In this case, the ROHC channel may have a plurality of ROHC context IDs, but an embodiment of the present invention proposes a 1: 1 mapping relationship. That is, one ROHC context ID is generated per service flow. At least one ROHC channel is configured in the terminal, and defines a ROHC parameter negotiation procedure for mapping the ROHC channel and a service flow. Therefore, since the ROHC channel and the service flow are mapped in a 1: 1 manner, no additional classification work is required to classify the service flow between the corresponding terminal or the base station.

1 is a diagram illustrating a schematic internal hierarchical structure of a communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the communication system includes a terminal 1 100, a terminal 2 110, and a base station 120. The terminals 1,2 (100,110) and the base station 120 are connected to the ROHC determination layer 130, the ROHC instance layer 140, the service flow search layer 150, and the ROHC channel layer 150, respectively. It is largely divided.

The ROHC determination layer 130 determines whether to apply ROHC of the corresponding IP packet header. The ROHC instance layer 140 that receives the result of applying the ROHC from the ROHC determination layer 130 is a logical entity that actually compresses and reconstructs the ROHC header.

The ROHC instance layer 140 includes a compression unit that performs ROHC on the header of the IP packet, a transmission feedback channel (FEEDBACK TX) that transmits a result of whether the compression of the packet is properly performed, and the IP packet to which the ROHC is applied. And a recovery feedback channel (FEEDBACK RX) for receiving a result of whether the header of the IP packet transmitted from the recovery unit is properly restored from the receiving side. The terminals may have at least one ROHC instance, but here, the case where the terminal 1 (100) has two ROHC instances, and the terminal 2 (110) has three ROHC instances as an example.

In addition, the ROHC instance 140 maps the ROHC channel for the IP packet to which the ROHC is applied and the corresponding service flow in a 1: 1 manner, and generates an ROHC context identifier for distinguishing the ROHC channel and the mapped service flow. Detailed operation thereof will be described in detail below.

The service flow search layer 150 searches for a corresponding service flow among a plurality of service flows supporting the terminal or the base station according to the transmission characteristics of the IP packet to which the ROHC received from the ROHC instance layer 140 is applied, Create a new service flow. Thereafter, the service flow search layer 150 transmits the searched or generated service flow to the controller of the ROHC instance 140. Thereafter, the controller maps the service flow to the ROHC channel in a 1: 1 ratio.

The ROHC channel layer 160 is a transmission / reception connection to which a compression unit and a restoration unit of a base station and a terminal are connected point to point. The ROHC channel, which is the transmission / reception connection, is a part proposed by the present invention, and a corresponding service flow is mapped according to a transmission characteristic of an IP packet. Here, since the signal flow between the terminal and the base station is the same, only a path between the terminal 1 100 and the base station 120 will be described as an example.

The compression unit of the terminal 1 (100) transmits the IP packet to which the ROHC is applied to the header through the ROHC channel 162 set up with the compression unit of the base station 120, and transmits the feedback of the terminal 1 (100) and the base station ( Information on whether the IP packet is normally compressed is transmitted through the ROHC feedback channel 164 set between the transmission feedbacks of the 120. The restoration unit of the terminal 1 (100) receives a packet whose header is ROHC restored through the ROHC channel 166 set up with the restoration unit of the base station 120, and receives the feedback of the terminal 1 (100) and the base station (120). Information about whether the ROHC compressed packet is normally restored through the ROHC feedback channel 168 established between the received feedbacks of the Although a plurality of service flows can be mapped per ROHC channel, this has a disadvantage of becoming complicated in implementation.

Therefore, a preferred embodiment of the present invention proposes a case where one service flow is mapped per ROHC channel.

The ROHC context ID of the service flow defined in the present invention is a classification identifier of the service flow mapped 1: 1 with the ROHC channel. That is, since one ROHC instance is mapped to each ROHC channel, a compression unit and a restoration unit connected to the ROHC channel established between the terminal and the base station are distinguished through the ROHC context ID. Since one service flow is mapped per ROHC context ID, the terminal and the base station search for the ROHC instance connected to the ROHC channel through the ROHC context without additional classification operation for identifying the service flow. The ROHC compressed and reconstructed packet is transmitted and received through the restoration unit and the compression unit of the ROHC channel set in the ROHC instance. In this case, one or more ROHC channels may be configured in one terminal.

In the 1: 1 mapping of the ROHC channel and the service flow, ROHC parameter negotiation is performed.

Specifically, when generating a corresponding service flow in which the ROHC channel between the terminal and the base station is mapped 1: 1, a DSA request and response (hereinafter referred to as DSA-REQ / RSP) Negotiation is carried out by passing ROHC parameter information through a message. In addition, when the generated existing service flow is to be set in the corresponding ROHC channel, a ROHC parameter is provided through a DSC request and response (Dynamic Service Change Request / Response, hereinafter, 'DSC-REQ / RSP') message. Negotiate by passing information.

The ROHC parameter is information of a corresponding service flow according to a transmission characteristic of a corresponding IP packet. The transmission characteristic includes an error rate or a bandwidth. The ROHC parameter is a value used only in an upper ROHC compression layer, and the MAC layer cannot interpret the service flow. The ROHC parameter is included in a payload TLV field of the DSA-REQ / RSP or DSC-REQ / RSP message as shown in Table 1 below.

Type Length Value Scope [145/146]. 47 variable ROHC Parameter Payload DSA-REQ, DSA-RSP DSC-REQ, DSC-RSP

2 is a diagram illustrating an internal configuration of an apparatus for performing mapping between a ROHC channel and a service flow according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the terminal or the base station includes the ROHC determiner 200, the ROHC instance block 210, and the service flow searcher 220.

The ROHC determining unit 200 receives an IP packet and determines whether to receive the ROHC compression of the received packet header, and determines whether the IP packet and the IP packet are compressed, the context ID generating unit 214 and the service flow. Transfer to the search unit 220.

The ROHC instance block 210 exists between the ROHC determiner 210 and the service flow searcher 220, and includes an ROHC controller 212 and a context ID generator 214. In this case, an ROHC channel is set between the ROHC controller 212 and the context ID generator 214.

The ROHC control unit 212 sets up an ROHC channel and transmits a ROHC parameter to the service flow search unit 220. Thereafter, the service flow search unit 220 receives the service flow determined according to the ROHC parameter and transfers the ROHC channel information and the received service flow information to the ROHC context ID generation unit 214.

When the IP packet received from the ROHC determining unit 200 is determined to apply ROHC, the context ID generating unit 214 compresses and restores the packet by applying ROHC to the header of the IP packet to perform the service flow search unit 220. ), And receives the compression and restoration result from the service flow search unit 220 as a ROHC feedback packet. In addition, the service flow search unit 220 maps the ROHC channel information received from the ROHC control unit 212 and the service flow to generate an ROHC context ID for identifying the service flow, and transmits it to the ROHC control unit 212. .

The service flow search unit 220 searches for or newly creates a service flow corresponding to the ROHC parameter received from the ROHC control unit 212. The service flow search unit 220 generates the searched or generated service flow as service flow information and transmits the generated service flow to the ROHC controller 212.

3 is a diagram illustrating a procedure for establishing an ROHC channel between a base station and a terminal according to an exemplary embodiment of the present invention. The above procedure is an operation of the ROHC determiner 300, the ROHC controller 310, the context ID generator 320, and the service flow searcher 330 of the terminal and the base station, respectively.

Referring to FIG. 3, in operation 335, when it is determined that ROHC is applied to a specific IP packet header, the ROHC determining unit 300 transmits to the ROHC controller 310 that ROHC is applied to the IP packet header.

In step 340, the ROHC controller 310 generates a ROHC channel, and in step 345, transmits a message for negotiating ROHC parameters to the service flow search unit 330. That is, the ROHC parameters for identifying a service flow which is a transmission connection for the IP packet to be mapped 1: 1 with the generated ROHC channel are DSA-REQ / when the ROHC channel is mapped with an existing generated service flow. Send and receive via RSP message, and when creating and mapping service flow, send and receive via DSC-REQ / RSP message. In this case, the format of the ROHC parameters is shown in Table 1 above.

In step 350, the service flow search unit 330 receiving the ROHC parameter searches for and selects a corresponding service flow according to a transmission characteristic of the IP packet, or generates a new service flow, and in step 355. Proceed. In step 355, the service flow search unit 330 transmits the selected or generated service flow information to the ROHC controller 310 to map the ROHC channel.

In step 360, the ROHC controller 310 maps the service flow and the ROHC channel, and the ROHC algorithm is applied to the corresponding IP packet while the ROHC channel has completed a preliminary procedure for delivering an IP packet to which an ROHC header is applied. The ROHC application information may be transmitted to the ROHC determining unit 300. Thereafter, the ROHC determining unit 300 transmits the corresponding ROHC applied IP packets to the ROHC context generator instead of the service flow search unit.

In step 365, the ROHC controller 310 transmits ROHC context ID generation information including the ROHC channel and the service flow information of the corresponding IP packet to the ROHC context ID generation unit 320.

In step 370, the ROHC context ID generation unit 320 maps the received ROHC channel and the service flow in a 1: 1 manner and generates an ROHC context ID for identifying the service flow.

Subsequently, when the terminal or the base station transmits the IP packet to which the ROHC is applied to the transmitting / receiving side, when the ROHC context ID to which the above service flow is mapped is generated, the corresponding service flow is mapped through the ROHC context ID. ROHC channel is available.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to an embodiment of the present invention, when a corresponding terminal or a base station generates a ROHC channel to which a service flow is mapped as described above, an IP packet to which the ROHC is applied is transmitted / received through an ROHC channel to which a corresponding service flow is mapped through the ROHC context ID. By the receiving side, there is no need to classify the service flow corresponding to the IP packet and the radio resources can be saved.

Claims (18)

In the channel setting method that supports header compression in a communication system, Mapping a header compression support channel of the header-compressed packet data and a service flow according to a transmission characteristic of the packet data one-to-one; And generating an identifier for classifying a service flow mapped to the header compression support channel. The method of claim 1, wherein the transmission characteristics, The channel setting method, characterized in that the error rate or bandwidth of the IP packet is included. The method of claim 2, wherein the mapping is performed. Searching for a service flow that satisfies a transmission characteristic among a plurality of service flows supporting the communication system, or generating a new service flow that satisfies the transmission characteristic. The method of claim 1, wherein the communication system, The channel setting method as claimed in claim 1, wherein the channel setting method is a portable internet system. The method of claim 1, wherein at least one header compression support channel is set in one terminal. The method of claim 1, wherein the identifier is, The channel setting method as claimed in claim 1, wherein one service flow is mapped to each service identifier. The method of claim 1, wherein the header compression, The channel setting method characterized in that the ROHC (RObust Header Compression). In a communication system, an apparatus for setting a channel that supports header compression, Header compression for generating a identifier for classifying a service compression mapped to the header compression support channel after mapping the header compression support channel of the header-compressed packet data and the service flow according to the transmission characteristic of the packet data one-to-one. The channel setting device configured to include a context identifier generator. The apparatus of claim 8, further comprising: a controller configured to generate the header compression support channel and to transmit a header compression parameter including information of the service flow to be mapped 1: 1 with the generated header compression support channel, to a service flow search unit; And a service flow search unit which receives the header compression parameter to generate a new service flow and transmits the generated service flow information to the controller. The method of claim 9, wherein the service flow search unit, And searching for a service flow according to the header compression parameter among service flows supported by the communication system and generating the service flow information as the service flow information. The method of claim 9, wherein the header compression parameter, When the header compression support channel is mapped with a previously generated service flow, transmission and reception through a DSA-REQ (Dynamic Service Addition Request / Response) / RSP message, When mapping with the newly generated service flow, the channel setting apparatus, characterized in that the transmission and reception via a DSC-REQ / RSP (Dynamic Service Change Request / Response) message. The method of claim 11, wherein the ROHC parameter, The channel setting apparatus, characterized in that included in the payload TLV field of the DSA-REQ / RSP or DSC-REQ / RSP message. The method of claim 9, wherein the control unit, And transmitting the service flow information and the generated header compression support channel information to a header compression context identifier generator. The method of claim 8, wherein the transmission characteristics, The channel setting apparatus, characterized in that the error rate or bandwidth of the IP packet is included. The method of claim 8, wherein the communication system, The channel setting apparatus, characterized in that the portable Internet system. The apparatus of claim 8, wherein at least one header compression support channel is set in one terminal. The method of claim 8, wherein the identifier, And one service flow is mapped to each service identifier. The method of claim 8, wherein the header compression, The channel setting apparatus, characterized in that ROHC (RObust Header Compression).

Images